Twins Lulu and Nana were born in October 2018 and a third baby is set to be born in 2019. All three have been edited to lower their suscepibility to HIV.
The gene in question, CCR5, has also been found to make mice smarter and helps the human brain recover after a stroke.
The Chinese scientist who carried out the experiments, He Jiankui, used CRISPR to modify the embryos which were then fertilized in vitro before being implanted into the mothers. He has been on unpaid leave since February.
CRISPR is a gene editing tool which uses a protein, Cas9, to cut DNA at the desired location.
In April, US scientists used CRISPR to edit T-cells to attack cancer, the first time the technology the technology was used in this way. Both patients relapsed after undergoing standard treatment.
In response to the controversy surrounding He’s experiments, Chinese lawmakers have proposed the introduction of gene-editing regulations into their civil code.
